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Birds are known to act as potential vectors for the exogenous dispersal of bryophyte diaspores. Given the totipotency of vegetative tissue of many bryophytes, birds could also contribute to endozoochorous bryophyte dispersal. Research has shown that fecal samples of the upland goose (Chloephaga picta) and white-bellied seedsnipe (Attagis malouinus) contain bryophyte fragments. Although few fragments from bird feces have been known to regenerate, the evidence for the viability of diaspores following passage through the bird intestinal tract remains ambiguous. We evaluated the role of endozoochory in these same herbivorous and sympatric bird species in sub-Antarctic Chile. We hypothesized that fragments of bryophyte gametophytes retrieved from their feces are viable and capable of regenerating new plant tissue. Eleven feces disk samples containing undetermined moss fragments from C. picta (N = 6) and A. malouinus (N = 5) and six moss fragment samples from wild-collected mosses (Conostomum tetragonum, Syntrichia robusta, and Polytrichum strictum) were grown ex situ in peat soil and in vitro using a agar Gamborg medium. After 91 days, 20% of fragments from A. malouinus feces, 50% of fragments from C. picta feces, and 67% of propagules from wild mosses produced new growth. The fact that moss diaspores remained viable and can regenerate under experimental conditions following the passage through the intestinal tracts of these robust fliers and altitudinal and latitudinal migrants suggests that sub-Antarctic birds might play a role in bryophyte dispersal. This relationship may have important implications in the way bryophytes disperse and colonize habitats facing climate change. [ABSTRACT FROM AUTHOR]

Abstract: The European rabbit (Oryctolagus cuniculus) is an alien herbivore in central Chile. Although its diet is poorly studied, this rabbit is known to consume native fruits and seeds, and thus it could act as a seed-dispersal agent. We evaluated the effect of endozoochory by rabbits on the survival and germination of seeds of a native shrub (Lithrea caustica, Anacardiaceae), as well as its consequences for seed dispersal. We extracted seeds by hand from parental shrubs, and compared the germination dynamics of seeds passing once and twice throughout the rabbit''s gut (simulating its coprophagy) versus control treatments (seeds not consumed). Additionally, in permanent 2×2m sampling plots placed in the wild, we evaluated the abundance of L. caustica seedlings and of its seeds in rabbit droppings. Results indicate that rabbits reduced seed survival to 82% on average with the first gut passage, and to an additional 52% with a second passage. Nevertheless, germination variables such as initiation time and germination, as well as final germination rate, increased significantly in comparison to non-ingested seeds. Sampling plots showed that L. caustica seedlings were concentrated principally underneath woody patches, which are then regarded as safe sites. Outside shrub cover, seedling abundance small, this indicates that open places are unsafe sites. We recorded that feces (and seeds contained) were deposited in higher proportion beneath woody cover. Thus, the native shrub L. caustica may be dispersed by alien rabbits through endozoochory, which provides legitimacy and efficiency in this dispersal service. Alien rabbits may fill a similar role played by native mammals, which have been reduced in abundance by human agency in central Chile. We suggest that the generalist syndrome, common among plants and dispersers, may be an arena of positive effects in ecological interactions between alien and native species. [Copyright &y& Elsevier]